Fix drill charge usage

The drills weren't taking the variable usage cost into account (either
the per-type base cost or the per-mode multiplier) when deciding whether
they have sufficient charge to use.  This could cause them to overshoot in
charge usage, although they would then clamp to zero rather than record
negative charge.  Also, for the Mk1 drill where the cost was assessed
correctly, the drill would refuse to discharge to exactly zero charge.

1 files changed, 32 insertions, 36 deletions

diff --git a/technic/tools/mining_drill.lua b/technic/tools/mining_drill.lua
index e3a01de..0471c71 100644
--- a/technic/tools/mining_drill.lua
+++ b/technic/tools/mining_drill.lua
@@ -1,9 +1,5 @@
-local mining_drill_max_charge      = 50000
-local mining_drill_mk2_max_charge  = 200000
-local mining_drill_mk3_max_charge  = 650000
-local mining_drill_power_usage     = 200
-local mining_drill_mk2_power_usage = 500
-local mining_drill_mk3_power_usage = 800
+local max_charge = {50000, 200000, 650000}
+local power_usage_per_node = {200, 500, 800}
 
 local S = technic.getter
 
@@ -140,9 +136,19 @@ local function drill_dig_it4 (pos,player)
 	drill_dig_it0 (pos,player)
 end
 
+local function cost_to_use(drill_type, mode)
+	local mult
+	if mode == 1 then
+		mult = 1
+	elseif mode <= 4 then
+		mult = 3
+	else
+		mult = 9
+	end
+	return power_usage_per_node[drill_type] * mult
+end
 
-local function drill_dig_it(pos, player, drill_type, mode)
-	local charge
+local function drill_dig_it(pos, player, mode)
 	if mode == 1 then
 		drill_dig_it0(pos, player)
 	end
@@ -220,18 +226,7 @@ local function drill_dig_it(pos, player, drill_type, mode)
 		end
 	end
 	
-	if drill_type==1 then charge=mining_drill_power_usage end
-	if drill_type==2 then 
-		if  mode==1 then charge=mining_drill_mk2_power_usage end
-		if (mode==2 or mode==3 or mode==4) then charge=mining_drill_mk2_power_usage*3 end
-	end
-	if drill_type==3 then 
-		if  mode==1 then charge=mining_drill_mk3_power_usage end
-		if (mode==2 or mode==3 or mode==4) then charge=mining_drill_mk3_power_usage*6 end
-		if mode==5 then charge=mining_drill_mk3_power_usage*9 end
-	end
 	minetest.sound_play("mining_drill", {pos = pos, gain = 1.0, max_hear_distance = 10,})
-	return charge
 end
 
 local function mining_drill_mk2_setmode(user,itemstack)
@@ -293,13 +288,13 @@ local function mining_drill_mk2_handler(itemstack, user, pointed_thing)
 	if pointed_thing.type ~= "node" or not meta.charge then
 		return
 	end
-	if meta.charge - mining_drill_power_usage > 0 then
+	local charge_to_take = cost_to_use(2, meta.mode)
+	if meta.charge >= charge_to_take then
 		local pos = minetest.get_pointed_thing_position(pointed_thing, above)
-		local charge_to_take = drill_dig_it(pos, user, 2, meta.mode)
+		drill_dig_it(pos, user, meta.mode)
 		meta.charge = meta.charge - charge_to_take
-		meta.charge = math.max(meta.charge, 0)
 		itemstack:set_metadata(minetest.serialize(meta))
-		technic.set_RE_wear(itemstack, meta.charge, mining_drill_mk2_max_charge)
+		technic.set_RE_wear(itemstack, meta.charge, max_charge[2])
 	end
 	return itemstack
 end
@@ -314,18 +309,18 @@ local function mining_drill_mk3_handler(itemstack, user, pointed_thing)
 	if pointed_thing.type ~= "node" or not meta.charge then
 		return
 	end
-	if meta.charge - mining_drill_power_usage > 0 then
+	local charge_to_take = cost_to_use(3, meta.mode)
+	if meta.charge >= charge_to_take then
 		local pos = minetest.get_pointed_thing_position(pointed_thing, above)
-		local charge_to_take = drill_dig_it(pos, user, 3, meta.mode)
+		drill_dig_it(pos, user, meta.mode)
 		meta.charge = meta.charge - charge_to_take
-		meta.charge = math.max(meta.charge, 0)
 		itemstack:set_metadata(minetest.serialize(meta))
-		technic.set_RE_wear(itemstack, meta.charge, mining_drill_mk3_max_charge)
+		technic.set_RE_wear(itemstack, meta.charge, max_charge[3])
 	end
 	return itemstack
 end
 
-technic.register_power_tool("technic:mining_drill", mining_drill_max_charge)
+technic.register_power_tool("technic:mining_drill", max_charge[1])
 
 minetest.register_tool("technic:mining_drill", {
 	description = S("Mining Drill Mk%d"):format(1),
@@ -339,12 +334,13 @@ minetest.register_tool("technic:mining_drill", {
 		if not meta or not meta.charge then
 			return
 		end
-		if meta.charge - mining_drill_power_usage > 0 then
+		local charge_to_take = cost_to_use(1, 1)
+		if meta.charge >= charge_to_take then
 			local pos = minetest.get_pointed_thing_position(pointed_thing, above)
-			charge_to_take = drill_dig_it(pos, user, 1, 1)
-			meta.charge = meta.charge - mining_drill_power_usage
+			drill_dig_it(pos, user, 1)
+			meta.charge = meta.charge - charge_to_take
 			itemstack:set_metadata(minetest.serialize(meta))
-			technic.set_RE_wear(itemstack, meta.charge, mining_drill_max_charge)
+			technic.set_RE_wear(itemstack, meta.charge, max_charge[1])
 		end
 		return itemstack
 	end,
@@ -359,10 +355,10 @@ minetest.register_tool("technic:mining_drill_mk2", {
 	end,
 })
 
-technic.register_power_tool("technic:mining_drill_mk2", mining_drill_mk2_max_charge)
+technic.register_power_tool("technic:mining_drill_mk2", max_charge[2])
 
 for i = 1, 4 do
-	technic.register_power_tool("technic:mining_drill_mk2_"..i, mining_drill_mk2_max_charge)
+	technic.register_power_tool("technic:mining_drill_mk2_"..i, max_charge[2])
 	minetest.register_tool("technic:mining_drill_mk2_"..i, {
 		description = S("Mining Drill Mk%d Mode %d"):format(2, i),
 		inventory_image = "technic_mining_drill_mk2.png^technic_tool_mode"..i..".png",
@@ -384,10 +380,10 @@ minetest.register_tool("technic:mining_drill_mk3", {
 	end,
 })
 
-technic.register_power_tool("technic:mining_drill_mk3", mining_drill_mk3_max_charge)
+technic.register_power_tool("technic:mining_drill_mk3", max_charge[3])
 
 for i=1,5,1 do
-	technic.register_power_tool("technic:mining_drill_mk3_"..i, mining_drill_mk3_max_charge)
+	technic.register_power_tool("technic:mining_drill_mk3_"..i, max_charge[3])
 	minetest.register_tool("technic:mining_drill_mk3_"..i, {
 		description = S("Mining Drill Mk%d Mode %d"):format(3, i),
 		inventory_image = "technic_mining_drill_mk3.png^technic_tool_mode"..i..".png",